Aircraft affect weather

The Dominion Post‘s Kiran Chug covers new research, published in the journal Science, linking weather pattens with airplane activity at major airports.

Image courtesy of Science/AAAS

An excerpt (read in full here):

Researchers link planes to rain increase

Aircraft are being blamed for affecting the weather at airports, with research published today suggesting they could be responsible for increasing rainfall over the terminals.

However, data gathered for New Zealand’s largest airports shows that, last year at least, local figures do not back up the theory.

American scientists have published their study in the journal Science.

The authors describe the phenomenon as having prevalence closer to polar regions, and back up the theory with an image of a cloud over West Antarctica with an apparent hole through it.

They use Heathrow and Charles de Gaulle airports as examples.

They note that, as planes flew through clouds, they often punched holes in those that contained “supercooled” water, which had stayed liquid below its freezing point.

Expansion and cooling of air behind an aircraft’s propeller or wings then resulted in temperature drops which could see cloud droplets form ice crystals.

The process could lead to a hole being produced in the cloud layer that expanded and resulted in more rainfall below the cloud, they said.

Scientist Ben Lilley, of the National Institute of Water and Atmospheric Research, said there were many instances of such holes in clouds being spotted.

“I can recall a few in the New Zealand papers at times. People wondering how there can be a gap in the clouds caused by aircraft.” The phenomenon was caused by the aircraft disturbing the air, but would need to happen in especially thin clouds for the effect to be witnessed, he said.

He doubted whether New Zealand’s airports were busy enough for the phenomenon to occur.